Preparation of substituted (Dichloromethyl) pyridined.

摘要

2- and 4-(Dichloromethyl)pyridines containing electron withdrawing substituents on the ring are prepared by the reaction of the corresponding 2- or 4- halopyridines with excess chloroform in the presence of a strong base in a medium containing a dipolar aprotic solvent or a phase transfer catalyst. 3-Chloro-5-(trifluoromethyl)-2-(dichloromethyl)pyridine, for example, is prepared by the reaction of 2,3-dichloro-5-(trifluoromethyl) pyridine with chloroform in the presence of sodium hydroxide and N-methylpyrrolidone. Substituted 2-(dichloromethyl)pyridines are useful as agricultural pesticides and as intermediates for the preparation of agricultural pesticides.